Giant clams are known in various tropical areas of the world such as the Australian Great Barrier Reef area and are recognised as forming part of the ecosystem of these areas. The numbers of giant clams are however decreasing due to commercial harvesting of the giant clams (often illegally) in order to satisfy the market for the flesh of the giant clam. To overcome this problem attempts have been made at the commercial farming of giant clams but such attempts have not always been successful due to the sensitivity of the clam, the difficulty of obtaining fertilized eggs, and the difficulty of raising juvenile clams from the fertilized egg stage. The clams are very sensitive to factors such as thermal shock and the fertilized eggs and/or juvenile clams can be attacked by various predators such as zoeplancta.